Devices for coupling vehicles together to transport newly manufactured or used vehicles between multiple locations are well known. Conventionally, a saddle, designed to couple a lead vehicle to a towed vehicle or combination of vehicles, is coupled to the lead vehicle. In truck applications, the saddle is conventionally mounted to either the fifth wheel, or to the frame of the lead truck. The saddle is then generally coupled to the front axle of the towed vehicle, such that the front axle of the towed vehicle is lifted from the ground, and the towed truck rolls on the rear wheels only. Alternatively, multiple saddles can be attached to additional trucks individually to allow for the transport of a maximum of four trucks in total.
Conventional saddle mount configurations generally include a saddle body used to secure the saddle mount to the frame of the towing vehicle and a saddle head for securing and retaining the front axle.
The saddle body of a conventional underslung saddle mount includes a middle section or cross member and opposing horizontal end/support plates extending outwardly from each end of the middle portion. Each end plate is welded to the middle section of the saddle body and contains apertures for receiving U-bolts or another securing mechanism for rigidly securing each plate to the towing or lead truck.
The middle portion or cross member of the saddle body is configured to support the saddle head on its upper surface. The saddle head is pivotally mounted to the top portion of the saddle body, which permits the towed truck to rotate in a horizontal plane in order to follow the lead truck through curves and corners during transport.
Although the saddle head is permitted to rotate or move during transport of the towed vehicle to accommodate movement of the lead vehicle, significant stress is exerted on the saddle body, and in particular, the end plates. Indeed, the rigidly secured end plates are subjected to both significant rotational and in plane loadings due at least in part to the weight of the towed vehicle, the movement and rotation of the towed vehicle with respect to the towing vehicle and the vibration and stress on the vehicles during transport at high speeds.
Prior art saddle mount constructions have exhibited significant deformation, and in some cases complete failure, at the end plates or support plate portions of the saddle body. Such deformation significant shortens the useful life of the saddle mount and may render the saddle mount inoperable or unsafe for its intended use.
Further, in certain prior art saddle mount designs, the welded portions of the saddle body, including the attachment of the end plates and structural reinforcing members within the saddle body, are located in positions that are not conspicuous to the vehicle operator or maintenance worker. As such, prior art saddle constructions are difficult to monitor or inspect for weld and structural integrity. Thus, it is difficult or impossible to detect damage to the saddle body or degradation of the welds thereon before noticeable, unrepairable damage occurs to the saddle body or to the saddle mount assembly.
In addition, such prior art saddle mount designs, the end plates are welded directly to the mid section of the saddle mount, limiting the surface area available for welding the joints together and/or limiting the ability to provide redundant or additional welded joints—thereby limiting the ability to protect against a catastrophic failure. In addition, direct, rigid connection of each end plate to the middle section of the saddle body may contribute to saddle mount failure, since such rigid and direct attachment does not provide sufficient flex or deflection between components to absorb or dissipate at least a portion of the load on the end plates.